Agricultural implement with combined down force and depth control

ABSTRACT

An agricultural implement system includes a down force cylinder configured to apply a downward force to a row unit, and a depth control cylinder configured to vary a penetration depth of a ground engaging tool of the row unit. The agricultural implement system also includes a valve assembly in fluid communication with the down force cylinder and the depth control cylinder. The valve assembly is configured to automatically adjust the downward force by varying fluid pressure within the down force cylinder based on fluid pressure within the depth control cylinder.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/976,787, entitled “AGRICULTURAL IMPLEMENT WITH COMBINED DOWN FORCEAND DEPTH CONTROL”, filed Dec. 21, 2015, which is a divisional of U.S.patent application Ser. No. 13/967,873, entitled “AGRICULTURAL IMPLEMENTWITH COMBINED DOWN FORCE AND DEPTH CONTROL”, filed Aug. 15, 2013, nowU.S. Pat. No. 9,215,837, which is a divisional of U.S. patentapplication Ser. No. 12/870,949, entitled “AGRICULTURAL IMPLEMENT WITHCOMBINED DOWN FORCE AND DEPTH CONTROL”, filed Aug. 30, 2010, now U.S.Pat. No. 8,522,889. Each of the foregoing applications is hereinincorporated by reference in its entirety.

BACKGROUND

The invention relates generally to ground working equipment, such asagricultural equipment, and more specifically, to an implementincorporating a combined down force and depth control system to maintaina substantially uniform seed deposition depth.

Generally, seeding implements are towed behind a tractor or other workvehicle. For example, a tongue of the implement may be connected to adrawbar of the tractor, or a mast of the implement may be connected to a3-point hitch of the tractor. These seeding implements typically includea ground engaging tool or opener that forms a seeding path for seeddeposition into the soil. In certain configurations, a gauge wheel ispositioned a vertical distance above the opener to establish a desiredtrench depth for seed deposition into the soil. As the implement travelsacross a field, the opener excavates a trench into the soil, and seedsare deposited into the trench. As will be appreciated, maintaining aconstant trench depth provides a substantially uniform soil cover whichenhances crop yields.

Certain implements include a gauge wheel rigidly mounted to theimplement at a desired vertical distance above the opener. In suchimplements, a significant down force may be applied to the gauge wheelto ensure that the opener remains at the desired penetration depthdespite variations in the terrain. Unfortunately, providing such a downforce to the gauge wheel may compact the soil adjacent to the seedtrench, thereby impeding crop growth. In addition, because the gaugewheel is pressed firmly against the soil surface, contact between thegauge wheel or the opener and any obstructions (e.g., rocks, clods,etc.) may induce an acceleration that propagates through the implement,thereby potentially reducing the operational life of certain componentswithin the implement.

BRIEF DESCRIPTION

The present invention provides an implement including a valve assemblyconfigured to maintain a contact force between a gauge wheel and thesoil by controlling a down force applied to a row unit. In an exemplaryembodiment, the agricultural implement includes a down force cylinderconfigured to apply a downward force to the row unit. The agriculturalimplement also includes a depth control cylinder configured to vary apenetration depth of a ground engaging tool of the row unit.Furthermore, the agricultural implement includes a valve assembly influid communication with the down force cylinder and the depth controlcylinder. The valve assembly is configured to automatically adjust thedownward force by varying fluid pressure within the down force cylinderbased on fluid pressure within the depth control cylinder. In thismanner, the contact force between the gauge wheel and the soil surfacemay be maintained despite variations in the terrain.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a perspective view of an exemplary agricultural implement;

FIG. 2 is a side view of an exemplary row unit that may be employedwithin the agricultural implement shown in FIG. 1;

FIG. 3 is a schematic diagram of an exemplary pneumatic systemconfigured to automatically adjust a down force on the row unit based onpneumatic pressure within a depth control cylinder;

FIG. 4 is a schematic diagram of an alternative pneumatic systemconfigured to automatically equalize a contact force of a press wheeland a gauge wheel; and

FIG. 5 is a schematic diagram of an alternative manual backup systemconfigured to facilitate manual control of the pneumatic system.

DETAILED DESCRIPTION

Turning now to the drawings, FIG. 1 is a perspective view of anagricultural implement 10. The implement 10 is designed to be towedbehind a work vehicle such as a tractor. The implement 10 includes atongue assembly 12 which is shown in the form of an A-frame hitchassembly. The tongue assembly 12 may include a hitch used to attach toan appropriate tractor hitch via a ball, clevis, or other coupling. Forexample, a tongue of the implement may be connected to a drawbar of thetractor, or a mast of the implement may be connected to a 3-point hitchof the tractor. The tongue assembly 12 is coupled to a tool bar 14 whichsupports multiple seeding implements or row units 16. As discussed indetail below, the agricultural implement 10 includes a pneumatic systemconfigured to automatically adjust a down force on each row unit 16based on fluid pressure within a depth control cylinder. For example, incertain embodiments, each row unit 16 includes an opener disk rotatablycoupled to a chassis of the row unit 16 and configured to engage soil.The row unit 16 also includes a gauge wheel assembly movably coupled tothe chassis and including a gauge wheel configured to rotate across asoil surface to limit a penetration depth of the opener disk into thesoil. In addition, the row unit 16 includes a depth control cylinderextending between the chassis and the gauge wheel assembly. The depthcontrol cylinder is configured to adjust the penetration depth of theopener disk by varying position of the gauge wheel relative to thechassis. A down force cylinder extending between the tool bar and thechassis is configured to vary a contact force between the gauge wheeland the soil surface. To adjust the contact force, a down force controlvalve is provided to regulate a flow of fluid to the down forcecylinder. The row unit 16 also includes an actuator coupled to the downforce control valve and in fluid communication with the depth controlcylinder. The actuator is configured to automatically adjust the contactforce by varying the flow of fluid through the down force control valvebased on fluid pressure within the depth control cylinder. In thismanner, the contact force between the gauge wheel and the soil surfacemay be maintained despite variations in the terrain.

FIG. 2 is a side view of an exemplary row unit 16 that may be employedwithin the agricultural implement 10 shown in FIG. 1. As illustrated,the row unit 16 includes elements 18 of a parallel linkage assembly,also known as a four bar linkage, configured to couple the row unit 16to the tool bar 14, while enabling vertical movement of the row unit 16.In addition, a down force cylinder 20 extends between a mounting bracket22 and a lower portion of the parallel linkage to establish a contactforce between the row unit 16 and the soil. The down force cylinder 20is configured to apply a force to the row unit 16 in a downwarddirection 24, thereby driving a ground engaging tool into the soil. Aswill be appreciated, a desired level of down force may vary based onsoil type, the degree of tillage applied to the soil, soil moisturecontent, amount of residue cover, and/or tool wear, among other factors.Because such factors may vary from one side of the implement 10 to theother, a different level of down force may be selected for each row unit16.

Furthermore, a desired level of down force may be dependent on the speedat which the row unit 16 is pulled across the field. For example, asspeed increases, the ground engaging tools may have a tendency to riseout of the ground due to the interaction between the soil and the tool.Consequently, a greater down force may be applied during higher speedoperation to ensure that the ground engaging tools remain at a desireddepth. In addition, the weight of the row unit 16 applies a force to theground engaging tools in the downward direction 24. However, as seedsand/or other products are transferred from a storage container withinthe row unit 16 to the soil, the weight of the row unit 16 decreases.Therefore, the down force cylinder 20 may apply a greater force to therow unit 16 to compensate. In certain embodiments, the down forcecylinder 20 may be coupled to a control system configured toautomatically regulate the pressure within the down force cylinder 20 tomaintain a desired contact force between the ground engaging tools andthe soil. Because each row unit 16 includes an independent down forcecylinder 20, the contact force may vary across the implement 10, therebyestablishing a substantially uniform seed deposition depth throughoutthe field.

In the present embodiment, the parallel linkage elements 18 arepivotally coupled to a chassis 26 and a frame 28. The frame 28 may beconfigured to support various elements of the row unit 16 such as ametering system and a product storage container, for example. Asillustrated, the chassis 26 supports an opener assembly 30, a soilclosing assembly 32, a press assembly 34, and a residue manager assembly36. In the present configuration, the opener assembly 30 includes agauge wheel assembly having a gauge wheel 38 and a rotatable arm 40which functions to movably couple the gauge wheel 38 to the chassis 26.The gauge wheel 38 may be positioned a vertical distance D above anopener disk 42 to establish a desired trench depth for seed depositioninto the soil. As the row unit 16 travels across a field, the openerdisk 42 excavates a trench into the soil, and seeds are deposited intothe trench. The opener assembly 30 also includes a depth controlcylinder 44 extending between the chassis 26 and the rotatable arm 40 ofthe gauge wheel assembly. The depth control cylinder 44 is configured toadjust the penetration depth D of the opener disk 42 by varying aposition of the gauge wheel 38 relative to the chassis 26. While oneopener assembly 30 is illustrated in the present embodiment, it shouldbe appreciated that alternative embodiments may include a pair of openerassemblies 30 positioned on opposite sides of the chassis 26. In suchconfigurations, the opener disks 42 may be angled toward one another toestablish a wider trench within the soil.

As will be appreciated, seeds may be deposited within the excavatedtrench via a seed tube extending between a metering system within theframe 28 and the soil. The seed tube exit may be positioned aft of theopener assembly 30 and forward of the closing assembly 32 such thatseeds flow into the trench. Closing disks 46 of the closing assembly 30push the excavated soil into the trench, thereby closing the trench. Asillustrated, the closing assembly 32 includes an arm 48 extendingbetween the chassis 26 and the closing disk 46. A closing disk cylinder50 is coupled to the arm 48 of the closing assembly 32, and configuredto regulate a contact force between the closing disk 46 and the soil.For example, a large contact force may be applied to effectively pushdense soil into the trench, while a relatively small contact force maybe applied to close a trench within loose soil. While one closing disk46 is shown in the present embodiment, it should be appreciated thatalternative embodiments may include a pair of disks 46. In addition,certain embodiments may employ closing wheels instead of the illustratedclosing disk 46.

As illustrated, a press wheel 52 of the press wheel assembly 34 ispositioned aft of the closing assembly 32, and serves to pack soil ontop of the deposited seeds. In the present embodiment, the press wheelassembly 34 includes an arm 54 extending between the chassis 26 and thepress wheel 52. A press wheel cylinder 56 is coupled to the arm 54 ofthe press wheel assembly 34, and configured to regulate a contact forcebetween the press wheel 52 and the soil. For example, in dry conditions,it may be desirable to firmly pack soil directly over the seeds to sealin moisture. In damp conditions, it may be desirable to leave the soilover the seeds fairly loose in order to avoid compaction which mayresult in seed crusting. The process of excavating a trench into thesoil, depositing seeds within the trench, closing the trench and packingsoil on top of the seeds establishes a row of planted seeds within afield. By employing multiple row units 16 distributed along the tool bar14, as shown in FIG. 1, multiple rows of seeds may be planted within thefield.

Certain embodiments of the row unit 16 may employ a residue managerassembly 36 to prepare the ground before seed deposition. Asillustrated, the residue manager assembly 36 includes a wheel 58 coupledto the chassis 26 by an arm 60. The wheel 58 includes tillage points orfingers 62 configured to break up crop residue on the soil surface. Aresidue manager cylinder 64 extends from a bracket 66 to the arm 60 ofthe residue manager assembly 36, and configured to regulate a contactforce between the wheel 58 and the soil. While a single residue managerwheel 58 is shown in the present embodiment, it should be appreciatedthat alternative embodiments may include a pair of wheels 58 angledtoward one another. In the present embodiment, the residue manager 36may serve as a shock absorber to dissipate row unit bounce caused bycontact with rocks or piles of residue, thereby protecting mechanicalcomponents of the row unit 16.

FIG. 3 is a schematic diagram of an exemplary pneumatic systemconfigured to automatically adjust the down force on the row unit basedon the pneumatic pressure within the depth control cylinder. Asillustrated, the present configuration employs a pair of depth controlcylinders. For example, the first depth control cylinder 44 may beutilized to adjust the position of the right gauge wheel 38 with respectto the chassis 26, while a second depth control cylinder 68 adjusts theposition of a left gauge wheel. Such an embodiment may employ acorresponding pair of opener disks positioned adjacent to each gaugewheel. In this configuration, the opener disks may be angled toward oneanother to establish a wider trench within the soil. While a pair ofdepth control cylinders 44 and 68 are employed in the presentconfiguration to adjust the penetration depth of a pair of opener disks,it should be appreciated that alternative configurations may employ asingle opener assembly with a single depth control cylinder.

In the present configuration, both of the depth control cylinders 44 and68 are in fluid communication with a depth control valve 70 configuredto regulate a pneumatic pressure within the depth control cylinders 44and 68. As illustrated, the depth control valve 70 is a threeposition/four way rotary leveling valve. The first position 72 isconfigured to facilitate a flow of air out of the depth controlcylinders 44 and 68, thereby raising the gauge wheels relative to thechassis 26. The second position 74 is configured to block the flow ofair into and out of the cylinders 44 and 68 to hold the gauge wheels ata desired position. The third position 76 is configured to facilitate aflow of air from a pneumatic source to the cylinders 44 and 68.Specifically, a pneumatic supply conduit 78 couples the depth controlvalve 70 to the pneumatic source (e.g., pump, compressor, etc.). In thethird position 76, the valve 70 enables air to flow from the pneumaticsupply conduit 78 to a pneumatic conduit 80 coupling the depth controlvalve 70 to the depth control cylinders 44 and 68. In the illustratedembodiment, the depth control cylinders 44 and 68 are double actingpneumatic cylinders. As illustrated, the pneumatic conduit 80 is influid communication with the cap end of each cylinder 44 and 68, and therod end of each cylinder 44 and 68 is in fluid communication with theatmosphere. Consequently, each cylinder 44 and 68 will operate as asingle acting cylinder. In this configuration, when the valve 70 is inthe third position 76, air flow from the pneumatic source pressurizesthe cap end of the cylinders 44 and 68, thereby inducing the piston rodto extend. Conversely, when the valve 70 is in the first position 72,air within the cap end of the cylinders 44 and 68 is allowed to exhaust,thereby facilitating retraction of the piston rod. In alternativeembodiments, the orientation of the cylinders 44 and 68 may be reversed,with the pneumatic conduit 80 coupled to the rod end of the cylinders.

As will be appreciated, because air is a compressible fluid, the depthcontrol cylinders 44 and 68 provide a suspension system for the row unit16. For example, as the row unit 16 is pulled across the field, thegauge wheels may move vertically in response to contact withobstructions in the soil. As the gauge wheels move, the air within thecylinders 44 and 68 is temporarily compressed, thereby partiallydissipating the force of impact. As will be appreciated, such aconfiguration may substantially reduce the wear associated with row unitvibrations, thereby extending the operation life of row unit components.

In the present configuration, the pneumatic conduit 80 extends betweenthe first depth control cylinder 44 and the second depth controlcylinder 68. In this configuration, both of the depth control cylinders44 and 68 are controlled by a single depth control valve 70. Inaddition, the pneumatic conduit 80 serves to reduce the magnitude ofgauge wheel movement in response to contact with an obstacle in thesoil. For example, if the right gauge wheel 38 contacts an obstacle, airwithin the cap end of the first depth control cylinder 44 will becompressed, thereby causing the right gauge wheel 38 to move verticallyupwards. In addition, because the first depth control cylinder 44 is influid communication with the second depth control cylinder 68 via thepneumatic conduit 80, air from the first depth control cylinder 44 willbe transferred to the cap end of the second depth control cylinder 68.Consequently, the piston rod of the second depth control cylinder 68will move vertically downward in response to the increased air pressure.As a result, the average depth of the opener disks within the soil maybe maintained. Similarly, if the right gauge wheel 38 encounters adepression within the soil, the left gauge wheel may move verticallyupwards due to the pneumatic connection between the cylinders.Therefore, the pneumatic conduit 80 serves to equalize variations insoil depth encountered by each gauge wheel 38.

As illustrated, the position of the depth control valve 70 is regulatedby a depth control actuator 84. In the present configuration, the depthcontrol actuator 84 is a single acting pneumatic cylinder. A pneumaticsupply conduit 86 is coupled to the cap end of the cylinder, and aspring (or other biasing device) urges the piston toward the cap end.Consequently, the depth control valve 70 may be actuated by increasingor decreasing pressure to the cap end of the depth control actuator 84.For example, in the present configuration, increasing pressure to theactuator 84 drives the depth control valve 70 toward the third position76, thereby providing air pressure to the depth control cylinders 44 and68 and decreasing the depth of the opener disk 42. Conversely,decreasing pressure to the actuator 84 enables the spring to drive thepiston toward the cap end, thereby driving the depth control valve 70 tothe first position 72 which releases air from the depth controlcylinders 44 and 68 and increases the depth of the opener disk 42.

In the present configuration, the pressure within the pneumatic supplyconduit 86 is controlled by a selection control valve 88. Asillustrated, the selection control valve 88 is a two position/two waypneumatic valve. The first position 90 is configured to block air flowthrough the valve, while the second position 92 facilitates air flow tothe depth control actuator 84. An electronic actuator 94 (e.g.,solenoid) regulates the position of the selection control valve 88. Theelectronic actuator 94 is communicatively coupled to an electroniccontrol unit (ECU) 96 which is configured to vary the position of theselection control valve 88 to achieve a desired pressure within theactuator 84. In certain embodiments, the ECU 96 is configured to measurethe penetration depth of the opener disks, and to vary pressure withinthe depth control cylinders 44 and 68 to compensate for a differencebetween a desired penetration depth and the measured penetration depth.

As illustrated, the row unit 16 includes a sensor assembly 97communicatively coupled to the ECU 96. In certain embodiments, thesensor assembly 97 may be configured to directly measure the penetrationdepth of the opener disks. For example, the sensor assembly 97 mayinclude an optical measurement system or a radio frequency transducerconfigured to measure the distance between the opener disks and the soilsurface. Alternatively, the sensor assembly 97 may include a linear orrotary potentiometer configured to measure the position of the gaugewheels relative to the chassis 26. Because the penetration depthcorresponds to the difference in height between the gauge wheels and theopener disks, measuring the gauge wheel position will facilitatecalculation of the penetration depth. In certain embodiments, the ECU 96may regulate pressure within the depth control cylinders 44 and 68 untila desired penetration depth is achieved.

The selection control valve 88 is fluidly coupled to an inflate/exhaustvalve 98 via a pneumatic supply conduit 100. In the present embodiment,the inflate/exhaust valve 98 is a three position/four way valve (e.g.,poppet valve, spool valve, etc.). The first position 102 is configuredto block air flow between the pneumatic supply conduit 100 and thepneumatic source, the second position 104 is configured to facilitateair flow out of the pneumatic supply conduit 100, and the third position106 is configured to fluidly couple the pneumatic source to thepneumatic supply conduit 100. The inflate/exhaust valve 98 also includestwo actuators 108 and 110 configured to adjust the position of the valve98. In the present embodiment, the first actuator 108 is a solenoidconfigured to drive the inflate exhaust valve 98 to the second position104, and the second actuator 110 is a solenoid configured to drive thevalve 98 to the third position 106. By adjusting the position of theinflate/exhaust valve 98, the ECU 96 may selectively provide air to thepneumatic supply conduit 100, maintain air pressure within the pneumaticsupply conduit 100, or release air from the pneumatic supply conduit100. As illustrated, a pressure sensor 112 is coupled to the pneumaticsupply conduit 100, and configured to output a signal to the ECU 96indicative of the pressure within the conduit 100. In thisconfiguration, the ECU 96 may provide a desired pressure to theselection control valve 88 by adjusting the position of theinflate/exhaust valve 98 via the actuators 108 and 110.

In the present embodiment, a depth adjustment system, including the ECU96 and the sensor assembly 97, is configured to maintain a desiredpenetration depth by increasing or decreasing pressure within theactuator 84. For example, if the planting depth is deeper than desired,the ECU 96 will activate the solenoid 94, thereby driving the selectioncontrol valve 88 to the second position 92. The ECU 96 will thenactivate the solenoid 110, thereby driving the inflate/exhaust valve 98to the second position 106. In the second position 106, air from thepneumatic source will flow into the pneumatic supply conduit 100. Withthe selection control valve 88 in the second position 92, air from thepneumatic supply conduit 100 will flow through the valve 88 and thepneumatic conduit 86 to the actuator 84 until a desired pressure withinthe actuator 84 is achieved, as measured by the pressure sensor 112.Next, the ECU 96 will instruct the electronic actuator 94 to transitionthe valve 88 to the first position 90, thereby blocking air flow betweenthe supply conduit 100 and the actuator 84. Consequently, pressurewithin the cap end of the actuator 84 will be maintained at the desiredpressure. As previously discussed, increasing air pressure to the capend of the actuator 84 drives the depth control valve 70 toward thethird position 76, thereby providing the depth control cylinders 44 and68 with air from the supply conduit 78. As a result, the gauge wheelswill be driven downwardly until a desired position is achieved.

Once the sensor assembly 97 determines that a desired penetration depthhas been reached, the ECU 96 will terminate air flow to the depthcontrol cylinders 44 and 68. Specifically, the ECU 96 will transitionthe selection control valve 88 to the second position 92, whichestablishes fluid communication between the conduits 86 and 100. The ECU96 will then transition the inflate/exhaust valve 98 to the secondposition 104, which facilitates air flow out of the pneumatic supplyconduit 100. Consequently, pressure within the cap end of the depthcontrol actuator 84 will decrease as air exhausts from the actuator 84.As previously discussed, the decrease in air pressure will drive thepiston rod of the actuator 84 toward the cap end, thereby inducing thedepth control valve 70 to transition to the second position 74 whichblocks air flow to the depth control cylinders 44 and 68. Once the ECU96 receives a signal from the pressure sensor 112 that the pressurewithin the cap end of the actuator 84 corresponds to a pressureindicative of the depth control valve 70 being in the second position74, the ECU 96 will transition the selection control valve 88 to thefirst position 90 which blocks flow to the pneumatic supply conduit 86.

Consequently, pressure within the actuator 84 will be maintained,thereby blocking air flow to the depth control cylinders 44 and 68. Itshould be appreciated that transitioning the selection control valve 88to the second position 92 and transitioning the inflate/exhaust valve 98to the first position 102 enables the pressure sensor 112 to measure thepressure within the cap end of the actuator 84.

In an alternative embodiment, the depth control valve 70 may be coupledto the gauge wheel arms 40 by a linkage such that movement of the gaugewheels 38 automatically adjusts pressure to the depth control cylinders44 and 68, thereby maintaining a desired penetration depth of the openerdisks 42. For example, if the planting depth is deeper than desired, theraised position of the gauge wheels 38 will drive the depth controlvalve 70 to the third position 76, thereby providing the depth controlcylinders 44 and 68 with air from the supply conduit 78. As a result,the gauge wheels 38 will be driven downwardly until a desired positionis achieved. As the gauge wheels 38 approach the desired position, thelinkage will drive the depth control valve 70 to the second position 74which blocks air flow to the depth control cylinders 44 and 68, therebyestablishing the desired planting depth. Conversely, if the plantingdepth is shallower than desired, the lowered position of the gaugewheels 38 will drive the depth control valve 70 to the first position72, thereby releasing air from the depth control cylinders 44 and 68. Asa result, the gauge wheels 38 will be driven upwardly until a desiredposition is achieved. As the gauge wheels 38 approach the desiredposition, the linkage will drive the depth control valve 70 to thesecond position 74 which blocks air flow from the depth controlcylinders 44 and 68, thereby establishing the desired planting depth. Aswill be appreciated, certain row units 16 include a single gauge wheel38, gauge wheel arm 40 and depth control cylinder 44. In suchembodiments, the depth control valve 70 will be coupled to the gaugewheel arm 40 by the linkage. However, if the row unit 16 employs twogauge wheels 38, two gauge wheel arms 40 and two depth control cylinders44 and 68, the linkage may be configured to mechanically average theposition of the gauge wheels 38 such that depth control valve positionis adjusted based on the average planting depth.

The illustrated row unit 16 also includes a blocking valve 114configured to maintain pressure within the depth control cylinders 44and 68 while the implement 10 is in a non-working position. For example,in certain configurations, the tool bar 14 may be raised above theground at a headland of a field such that the row units 16 disengage thesoil. In this non-working position, the implement 10 may be rotated atthe headland and aligned with the next series of rows without the rowunits 16 excavating trenches or depositing seeds within the headland.Maintaining air pressure within the depth control cylinders 44 and 68while the implement 10 is in the non-working position ensures that thegauge wheel position will remain substantially unchanged when the rowunit reengages the soil. As illustrated, the blocking valve 114 includesa first position 116 that facilitates air flow to the depth controlcylinders 44 and 68, and a second position 118 that blocks the air flow.In the present embodiment, the blocking valve 114 is actuated by theparallel linkage 18 coupled to the tool bar 14. Consequently, when thetool bar 14 transitions to the non-working position, the blocking valve114 is driven to the second position 118 which blocks air flow.Conversely, when the tool bar 14 is in the working position, theblocking valve 114 is driven to the first position 116 such that thepressure to the cylinders 44 and 68 may be regulated as described above.

In the illustrated embodiment, a down force control valve 120 is influid communication with the down force cylinder 20. The down forcecontrol valve 120 is configured to regulate a pressure within the downforce cylinder 20, thereby adjusting the contact force between the gaugewheels and the soil. In the present embodiment, the down force controlvalve 120 is a three position/four way rotary leveling valve. The firstposition 122 is configured to block air flow to the down force cylinder20, the second position 124 is configured to facilitate air flow intothe down force cylinder 20, and the third position 126 is configured tofacilitate air flow out of the down force cylinder 20. As illustrated, apneumatic conduit 128 extends between the down force control valve 120and the pneumatic supply conduit 78, and a pneumatic conduit 130 extendsbetween the down force control valve 120 and the down force cylinder 20.Consequently, while the down force control valve 120 is in the secondposition 124, air may flow from the pneumatic source to the cap end ofthe down force cylinder 20 via the conduits 78, 128 and 130, and thevalve 120.

As illustrated, the position of the down force control valve 120 isregulated by a down force control actuator 132. In the presentconfiguration, the down force control actuator 132 is a double actingpneumatic cylinder having a pneumatic supply conduit 134 coupled to therod end of the cylinder. In this configuration, the down force controlvalve 120 may be actuated by increasing or decreasing pressure to therod end of the actuator 132. For example, in the present configuration,increasing pressure to the rod end drives the down force control valve120 toward the second position 124, thereby providing air pressure tothe down force cylinder 20. Conversely, decreasing pressure to theactuator 132 allows pressure within the cap end to urge the pistontoward the rod end, thereby driving the down force control valve 120 tothe third position 126 that releases air from the down force cylinder20.

In the present configuration, the pressure within the pneumatic supplyconduit 134 is controlled by a selection control valve 136. Asillustrated, the selection control valve 136 is a two position/two waypneumatic valve. The first position 138 is configured to block air flowthrough the valve, while the second position 140 facilitates air flow tothe down force control actuator 132. An electronic actuator 142 (e.g.,solenoid) regulates the position of the selection control valve 136. Theelectronic actuator 142 is communicatively coupled to the ECU 96 whichis configured to vary the position of the selection control valve 136 toachieve a desired pressure within the actuator 132. Consequently, theECU 96 may automatically regulate the force applied by the down forcecylinder 20. For example, an operator may input a desired down forceinto a user interface 144. The user interface 144 may then output asignal to the ECU 96 indicative of the desired down force such that theECU 96 adjusts the pressure within the down force actuator 132 toachieve the desired force. In certain embodiments, the sensor assembly97 may be configured to measure the down force applied by the down forcecylinder 20. For example, the sensor assembly 97 may include a pressuresensor in fluid communication with the conduit 130 and configured tooutput a signal indicative of the force applied by the down forcecylinder 20. In such embodiments, the ECU 96 may automatically regulatepressure within the actuator 132 to maintain the desired down force.

The selection control valve 136 is fluidly coupled to theinflate/exhaust valve 98 via the pneumatic supply conduit 100. Aspreviously discussed, the inflate/exhaust valve 98 is a threeposition/four way valve. The first position 102 is configured to blockair flow between the pneumatic supply conduit 100 and the pneumaticsource, the second position 104 is configured to facilitate air flow outof the pneumatic supply conduit 100, and the third position 106 isconfigured to fluidly couple the pneumatic source to the pneumaticsupply conduit 100. By adjusting the position of the inflate/exhaustvalve 98, the ECU 96 may selectively provide air to the pneumatic supplyconduit 100, maintain air pressure within the pneumatic supply conduit100, or release air from the pneumatic supply conduit 100. In thisconfiguration, the ECU 96 may provide a desired pressure to theselection control valve 136 by adjusting the position of theinflate/exhaust valve 98 via the actuators 108 and 110.

As previously discussed, the ECU 96 is configured to automaticallyregulate the force applied by the down force cylinder 20. For example,if the force is lower than desired, the ECU 96 will activate thesolenoid 142, thereby driving the selection control valve 136 to thesecond position 140. The ECU 96 will then activate the solenoid 110,thereby driving the inflate/exhaust valve 98 to the second position 106.In the second position 106, air from the pneumatic source will flow intothe pneumatic supply conduit 100. With the selection control valve 136in the second position 140, air from the pneumatic supply conduit 100will flow through the valve 136 and the pneumatic conduit 134 to theactuator 132 until a desired pressure within the actuator 132 isachieved, as measured by the pressure sensor 112. Next, the ECU 96 willinstruct the electronic actuator 142 to transition the valve 136 to thefirst position 138, thereby blocking air flow between the supply conduit100 and the actuator 132. Consequently, pressure within the rod end ofthe actuator 132 will be maintained at the desired pressure. Aspreviously discussed, increasing air pressure to the rod end of theactuator 132 drives the down force control valve 120 toward the secondposition 124, thereby providing the down force cylinder 20 with air fromthe supply conduits 78 and 128. As a result, the force applied by thedown force cylinder 20 will increase until the desired force isachieved.

Once the desired down force is reached, the ECU 96 will terminate airflow to the down force cylinder 20. Specifically, the ECU 96 willtransition the selection control valve 136 to the second position 140which establishes fluid communication between the conduits 134 and 100.The ECU 96 will then transition the inflate/exhaust valve 98 to thesecond position 104 which facilitates air flow out of the pneumaticsupply conduit 100. Consequently, pressure within the rod end of thedown force actuator 132 will decrease as air exhausts from the actuator132. As previously discussed, the decrease in air pressure will drivethe piston rod of the actuator 132 toward the rod end, thereby inducingthe down force control valve 120 to transition to the first position 122which blocks air flow to the down force cylinder 20. Once the ECU 96receives a signal from the pressure sensor 112 that the pressure withinthe rod end of the actuator 132 corresponds to a pressure indicative ofthe down force control valve 120 being in the first position 122, theECU 96 will transition the selection control valve 136 to the firstposition 138 which blocks flow to the pneumatic supply conduit 134.Consequently, pressure within the actuator 132 will be maintained,thereby blocking air flow to the down force cylinder 20. It should beappreciated that transitioning the selection control valve 136 to thesecond position 140 and transitioning the inflate/exhaust valve 98 tothe first position 102 enables the pressure sensor 112 to measure thepressure within the rod end of the actuator 132.

As previously discussed, the down force actuator 132 is a double actingcylinder having fluid connections to both the rod end and the cap end.Consequently, in addition to controlling the actuator 132 by varying theair pressure within the rod end, as described above, the actuator 132may be controlled by varying the air pressure within the cap end. In theillustrated embodiment, a pneumatic conduit 145 extends between thedepth control conduit 80 and the cap end of the down force actuator 132.In this configuration, a valve assembly, including the actuator 132 andthe down force control valve 120, facilitates automatic adjustment ofthe contact force between the gauge wheels and the soil by varying thepressure within the down force cylinder 20 based on air pressure withinthe depth control cylinders 44 and 68.

A desired penetration depth of the opener disks may be established byvarying the position of the gauge wheels. Specifically, pressure withinthe cap end of the depth control cylinders 44 and 68 may be adjusted toachieve the desired gauge wheel position. However, with the row unit 16in a steady state condition (e.g., not moving, moving along asubstantially flat surface, etc.), the pressure within the cap end ofthe depth control cylinders 44 and 68 will remain substantiallyconstant. Consequently, the pressure within the cap end of the downforce actuator 132 will remain substantially constant due to the fluidconnection between the cylinders 44 and 68 and the actuator 132. As aresult, while the row unit 16 is in a steady state condition, the downforce may be regulated as described above, i.e., by varying pressure tothe rod end of the actuator 132. However, once the selection controlvalve 136 is in the first position 138 such that air flow to the rod endof the actuator 132 is blocked, any subsequent change to the pressurewithin the cap end of the actuator 132 will drive the down force controlvalve 120 toward the second position 124 or the third position 126.

Certain variations in the terrain may induce the gauge wheels to moveupwardly relative to the opener disks. In such a situation, the ECU 96or the linkage between the depth control valve 70 and the gauge wheelarm 40 may automatically increase pressure to the depth controlcylinders 44 and 68 to compensate, thereby maintaining the desiredopener disk penetration depth. However, increasing pressure to thecylinders 44 and 68 also increases the contact force between the gaugewheels and the soil. As previously discussed, excessive contact forcemay result in compacted soil which impedes the growth of seeds depositedwithin the soil. Consequently, the valve assembly may automaticallyreduce the force applied by the down force cylinder 20 in response to anincrease in pressure within the cylinders 44 and 68. In this manner, thecontact force between the gauge wheels and the soil may be maintaineddespite variations in the terrain.

For example, an increase in pressure within the cap end of the depthcontrol cylinders 44 and 68 will increase pressure within the cap end ofthe down force actuator 132 via the fluid connection established by thepneumatic conduit 145. As will be appreciated, the pressure increasewithin the cap end of the actuator 132 will drive the down force controlvalve 120 toward the third position 126 that facilitates air flow fromthe down force cylinder 20. As a result, the force applied by thecylinder 20 will decrease, thereby resulting in a reduced contact forcebetween the gauge wheels and the soil. As the contact force decreases,the pressure within the cap end of the depth control cylinders 44 and 68will decrease. Consequently, the pressure within the cap end of theactuator 132 will be reduced, thereby transitioning the down forcecontrol valve 120 back to the first position 122 that blocks air flow tothe down force cylinder 20. In this manner, the contact force betweenthe gauge wheels and the soil may be automatically maintained despite anincrease in pressure within the depth control cylinders 44 and 68.

Conversely, certain conditions may induce the gauge wheels to movedownwardly relative to the opener disks. For example, as the quantity ofseed and/or fertilizer within the row unit 16 decreases, the penetrationdepth of the opener disks into the soil will be reduced due to thedecrease in row unit weight. To compensate, the depth control valve 70may decrease pressure to the depth control cylinders 44 and 68, therebyraising the gauge wheels relative to the opener disks. However,decreasing pressure to the cylinders 44 and 68 also decreases thecontact force between the gauge wheels and the soil. If the contactforce is too low, the opener disks may rise out of the ground.Consequently, the valve assembly may automatically increase the forceapplied by the down force cylinder 20 in response to the decrease inpressure within the cylinders 44 and 68. In this manner, the contactforce between the gauge wheels and the soil may be maintained despitevariations in row unit weight.

For example, a decrease in pressure within the cap end of the depthcontrol cylinders 44 and 68 will decrease pressure within the cap end ofthe down force actuator 132 via the fluid connection established by thepneumatic conduit 145. As will be appreciated, the pressure decreasewithin the cap end of the actuator 132 will drive the down force controlvalve 120 to the second position 124 that facilitates air flow into thecylinder 20 from the pneumatic conduit 128. As a result, the forceapplied by the cylinder 20 will increase, thereby resulting in anincreased contact force between the gauge wheels and the soil. As thecontact force increases, the pressure within the cap end of the depthcontrol cylinders 44 and 68 will increase. Consequently, the pressurewithin the cap end of the actuator 132 will rise, thereby transitioningthe down force control valve 120 back to the first position 122 thatblocks air flow to the down force cylinder 20. In this manner, thecontact force between the gauge wheels and the soil may be automaticallymaintained despite a decrease in pressure within the depth controlcylinders 44 and 68.

As will be appreciated, the down force actuator 132 may be particularlyconfigured to induce a desired degree of movement within the down forcecontrol valve 120 in response to variations in depth control cylinderpressure. For example, the length and/or width of the double actingcylinder may be configured to achieve a desired dynamic response (e.g.,piston rod movement in response to pressure within the cap end). Inaddition, the actuator 132 may include valves and/or springs configuredto bias the piston to the cap end or the rod end of the cylinder,thereby establishing a desired relationship between pressure and pistonrod movement.

The illustrated row unit 16 also includes a blocking valve 146configured to maintain pressure within the down force cylinder 20 whilethe implement 10 is in the non-working position. As previouslydiscussed, the tool bar 14 may be raised above the ground at a headlandof a field such that the row units 16 disengage the soil. In thisnon-working position, the implement 10 may be rotated at the headlandand aligned with the next series of rows without the row units 16excavating trenches or depositing seeds within the headland. Maintainingair pressure within the down force cylinder 20 while the implement 10 isin the non-working position ensures that the down force will remainsubstantially unchanged when the row unit reengages the soil. Asillustrated, the blocking valve 146 includes a first position 148 thatfacilitates air flow to the down force cylinder 20, and a secondposition 150 that blocks the air flow. In the present embodiment, theblocking valve 146 is actuated by the parallel linkage 18 coupled to thetool bar 14. Consequently, when the tool bar 14 transitions to thenon-working position, the blocking valve 146 is driven to the secondposition 150 which blocks air flow. Conversely, when the tool bar 14 isin the working position, the blocking valve 146 is driven to the firstposition 148 such that the pressure to the down force cylinder 20 may beregulated as described above.

In the illustrated embodiment, the row unit 16 also includes a pressurerelief valve 152 in fluid communication with the pneumatic conduit 130.In this configuration, if the pressure within the cap end of thecylinder 20 exceeds a predetermined level, the pressure relief valve 152will open, thereby reducing the pressure in the cylinder 20. Forexample, if the row unit 16 encounters a rock or other obstruction inthe soil, the row unit 16 will be driven upwardly. As a result, airpressure within the cap end of the cylinder 20 will increase rapidly. Insuch a situation, the pressure relief valve 152 will open, therebydecreasing the pressure and substantially reducing or eliminating thepossibility of excessive wear of pneumatic components. In alternativeembodiments, the pneumatic components may be particularly configured toresist pressures associated with full upward displacement of the rowunit 16. In such embodiments, the pressure relief valve 152 may beomitted.

The illustrated embodiment also includes a closing disk cylinder 50configured to regulate a contact force between the closing disks and thesoil. As illustrated, a pneumatic supply conduit 154 extends between acap end of the cylinder 50 and a selection control valve 156. Similar toadjusting the pressure within the actuators 84 and 132, the ECU 96 isconfigured to regulate the pressure within the closing disk cylinder 50by operating the selection control valve 156 and the intake/exhaustvalve 98. For example, an operator may input a desired contact forceinto the user interface 144. The user interface 144 may then output asignal to the ECU 96 indicative of the desired contact force such thatthe ECU 96 adjusts the pressure within the closing disk cylinder 50 toachieve the desired force. In certain embodiments, the sensor assembly97 may be configured to measure a degree of soil compaction. Forexample, the sensor assembly 97 may include a soil profile sensor orother device capable of quantifying soil compaction and outputting asignal indicative of soil compaction to the ECU 96. Alternatively, acourse estimation of soil compaction may be determined by measuring thepressure within the down force cylinder 20. The ECU 96 may then computethe desired contact force based on the degree of compaction. Forexample, a large contact force may be applied to effectively push densesoil into the trench, while a relatively small contact force may beapplied to close a trench within loose soil. In this manner, the ECU 96may automatically adjust air pressure to the closing disk cylinder 50based on the detected soil compaction.

In the present configuration, the pressure within the closing diskcylinder 50 is controlled by the selection control valve 156. Asillustrated, the selection control valve 156 is a two position/two waypneumatic valve. The first position 158 is configured to block air flowthrough the valve, while the second position 160 facilitates air flow tothe closing disk cylinder 50. An electronic actuator 162 (e.g.,solenoid) regulates the position of the selection control valve 156. Theelectronic actuator 162 is communicatively coupled to the ECU 96 whichis configured to vary the position of the selection control valve 156 toachieve a desired pressure within the cylinder 50. Consequently, the ECU96 may automatically regulate the contact force applied by the closingdisk cylinder 50.

The selection control valve 156 is fluidly coupled to theinflate/exhaust valve 98 via the pneumatic supply conduit 100. Aspreviously discussed, the inflate/exhaust valve 98 is a threeposition/four way valve. The first position 102 is configured to blockair flow between the pneumatic supply conduit 100 and the pneumaticsource, the second position 104 is configured to facilitate air flow outof the pneumatic supply conduit 100, and the third position 106 isconfigured to fluidly couple the pneumatic source to the pneumaticsupply conduit 100. By adjusting the position of the inflate/exhaustvalve 98, the ECU 96 may selectively provide air to the pneumatic supplyconduit 100, maintain air pressure within the pneumatic supply conduit100, or release air from the pneumatic supply conduit 100. In thisconfiguration, the ECU 96 may provide a desired pressure to the closingdisk cylinder 50 by adjusting the position of the inflate/exhaust valve98 via the actuators 108 and 110.

For example, to increase pressure to the cap end of the closing diskcylinder 50, the ECU 96 will activate the solenoid 162, thereby drivingthe selection control valve 156 to the second position 160. The ECU 96will then activate the solenoid 110, thereby driving the inflate/exhaustvalve 98 to the second position 106. In the second position 106, airfrom the pneumatic source will flow into the pneumatic supply conduit100. With the selection control valve 156 in the second position 160,air from the pneumatic supply conduit 100 will flow through the valve156 and the pneumatic conduit 154 to the closing disk cylinder 50 untila desired pressure within the cylinder 50 is achieved, as measured bythe pressure sensor 112. Next, the ECU 96 will instruct the electronicactuator 162 to transition the valve 156 to the first position 158,thereby blocking air flow between the supply conduit 100 and thecylinder 50. Consequently, pressure within the cap end of the cylinder50 will be maintained at the desired pressure.

Conversely, to decrease pressure within the cap end of the closing diskcylinder 50, the ECU 96 will transition the selection control valve 156to the second position 160 which establishes fluid communication betweenthe conduits 154 and 100. The ECU 96 will then transition theinflate/exhaust valve 98 to the second position 104 which facilitatesair flow out of the pneumatic supply conduit 100. Consequently, pressurewithin the cap end of the closing disk cylinder 50 will decrease as airexhausts from the cylinder 50. Once the ECU 96 receives a signal fromthe pressure sensor 112 that the pressure within the cap end of theclosing disk cylinder 50 has reached a desired level, the ECU 96 willtransition the selection control valve 156 to the first position 158which blocks flow to the pneumatic supply conduit 154. Consequently,pressure within the closing disk cylinder 50 will be maintained. In thismanner, the ECU 96 may automatically regulate the contact force appliedby the closing disk cylinder 50 in response to either operator input ordetected soil compaction. It should be appreciated that transitioningthe selection control valve 156 to the second position 160 andtransitioning the inflate/exhaust valve 98 to the first position 102enables the pressure sensor 112 to measure the pressure within the capend of the closing disk cylinder 50.

In addition, the illustrated embodiment includes a press wheel cylinder56 configured to regulate a contact force between the press wheel andthe soil. As illustrated, a pneumatic supply conduit 166 extends betweena cap end of the cylinder 56 and a selection control valve 168. Similarto adjusting the pressure within the closing disk cylinder 50, the ECU96 is configured to regulate the pressure within the press wheelcylinder 56 by operating the selection control valve 168 and theintake/exhaust valve 98. For example, an operator may input a desiredcontact force into the user interface 144. The user interface 144 maythen output a signal to the ECU 96 indicative of the desired contactforce such that the ECU 96 adjusts the pressure within the press wheelcylinder 56 to achieve the desired force. In certain embodiments, thesensor assembly 97 may be configured to measure soil moisture content.For example, the sensor assembly 97 may include a soil density sensor orother device capable of quantifying soil moisture and outputting asignal indicative of soil moisture to the ECU 96. In such embodiments,the ECU 96 may compute the desired contact force based on the signal.For example, in dry conditions, it may be desirable to firmly pack soildirectly over the seeds to seal in moisture. In damp conditions, it maybe desirable to leave the soil over the seeds fairly loose in order toavoid compaction which may result in seed crusting. In this manner, theECU 96 may automatically adjust air pressure to the press wheel cylinder56 based on the detected soil moisture level.

In the present configuration, the pressure within the press wheelcylinder 56 is controlled by the selection control valve 168. Asillustrated, the selection control valve 168 is a two position/two waypneumatic valve. The first position 170 is configured to block air flowthrough the valve, while the second position 172 facilitates air flow tothe press wheel cylinder 56. An electronic actuator 174 (e.g., solenoid)regulates the position of the selection control valve 168. Theelectronic actuator 174 is communicatively coupled to the ECU 96 whichis configured to vary the position of the selection control valve 168 toachieve a desired pressure within the cylinder 56. Consequently, the ECU96 may automatically regulate the contact force applied by the presswheel cylinder 56.

The selection control valve 168 is fluidly coupled to theinflate/exhaust valve 98 via the pneumatic supply conduit 100. Aspreviously discussed, the inflate/exhaust valve 98 is a threeposition/four way valve. The first position 102 is configured to blockair flow between the pneumatic supply conduit 100 and the pneumaticsource, the second position 104 is configured to facilitate air flow outof the pneumatic supply conduit 100, and the third position 106 isconfigured to fluidly couple the pneumatic source to the pneumaticsupply conduit 100. By adjusting the position of the inflate/exhaustvalve 98, the ECU 96 may selectively provide air to the pneumatic supplyconduit 100, maintain air pressure within the pneumatic supply conduit100, or release air from the pneumatic supply conduit 100. In thisconfiguration, the ECU 96 may provide a desired pressure to the presswheel cylinder 56 by adjusting the position of the inflate/exhaust valve98 via the actuators 108 and 110.

For example, to increase pressure to the cap end of the press wheelcylinder 56, the ECU 96 will activate the solenoid 174, thereby drivingthe selection control valve 168 to the second position 172. The ECU 96will then activate the solenoid 110, thereby driving the inflate/exhaustvalve 98 to the second position 106. In the second position 106, airfrom the pneumatic source will flow into the pneumatic supply conduit100. With the selection control valve 168 in the second position 172,air from the pneumatic supply conduit 100 will flow through the valve168 and the pneumatic conduit 166 to the press wheel cylinder 56 until adesired pressure within the cylinder 56 is achieved, as measured by thepressure sensor 112. Next, the ECU 96 will instruct the electronicactuator 174 to transition the valve 168 to the first position 170,thereby blocking air flow between the supply conduit 100 and thecylinder 56. Consequently, pressure within the cap end of the cylinder56 will be maintained at the desired pressure.

Conversely, to decrease pressure within the cap end of the press wheelcylinder 56, the ECU 96 will transition the selection control valve 168to the second position 172 which establishes fluid communication betweenthe conduits 166 and 100. The ECU 96 will then transition theinflate/exhaust valve 98 to the second position 104 which facilitatesair flow out of the pneumatic supply conduit 100. Consequently, pressurewithin the cap end of the press wheel cylinder 56 will decrease as airexhausts from the cylinder 56. Once the ECU 96 receives a signal fromthe pressure sensor 112 that the pressure within the cap end of thepress wheel cylinder 56 has reached a desired level, the ECU 96 willtransition the selection control valve 168 to the first position 170which blocks flow to the pneumatic supply conduit 166. Consequently,pressure within the press wheel cylinder 56 will be maintained. In thismanner, the ECU 96 may automatically regulate the contact force appliedby the press wheel cylinder 56 in response to either operator input ordetected soil moisture/density. It should be appreciated thattransitioning the selection control valve 168 to the second position 172and transitioning the inflate/exhaust valve 98 to the first position 102enables the pressure sensor 112 to measure the pressure within the capend of the press wheel cylinder 56.

The illustrated embodiment also includes a residue manager cylinder 64configured to regulate a contact force between the residue manager andthe soil. As illustrated, a pneumatic supply conduit 178 extends betweena cap end of the cylinder 64 and a selection control valve 180. Similarto adjusting the pressure within the closing disk cylinder 50, the ECU96 is configured to regulate the pressure within the residue managercylinder 64 by operating the selection control valve 180 and theintake/exhaust valve 98. For example, an operator may input a desiredcontact force into the user interface 144. The user interface 144 maythen output a signal to the ECU 96 indicative of the desired contactforce such that the ECU 96 adjusts the pressure within the residuemanager cylinder 64 to achieve the desired force. In certainembodiments, the sensor assembly 97 may be configured to measure apercentage of residue cover. For example, the sensor assembly 97 mayinclude an optical sensor or other device capable of quantifying residuecover and outputting a signal indicative of residue coverage percentageto the ECU 96. In such embodiments, the ECU 96 may compute the desiredcontact force based on the signal. For example, if the residue cover isgreater than the desired percentage, the ECU 96 may increase contactforce. Conversely, if the residue cover is less than the desiredpercentage, the ECU 96 may decrease contact force. In this manner, theECU 96 may automatically adjust air pressure to the residue managercylinder 64 based on the detected residue coverage percentage.

In the present configuration, the pressure within the residue managercylinder 64 is controlled by the selection control valve 180. Asillustrated, the selection control valve 180 is a two position/two waypneumatic valve. The first position 182 is configured to block air flowthrough the valve, while the second position 184 facilitates air flow tothe residue manager cylinder 64. An electronic actuator 186 (e.g.,solenoid) regulates the position of the selection control valve 180. Theelectronic actuator 186 is communicatively coupled to the ECU 96 whichis configured to vary the position of the selection control valve 180 toachieve a desired pressure within the cylinder 64. Consequently, the ECU96 may automatically regulate the contact force applied by the residuemanager cylinder 64.

The selection control valve 180 is fluidly coupled to theinflate/exhaust valve 98 via the pneumatic supply conduit 100. Aspreviously discussed, the inflate/exhaust valve 98 is a threeposition/four way valve. The first position 102 is configured to blockair flow between the pneumatic supply conduit 100 and the pneumaticsource, the second position 104 is configured to facilitate air flow outof the pneumatic supply conduit 100, and the third position 106 isconfigured to fluidly couple the pneumatic source to the pneumaticsupply conduit 100. By adjusting the position of the inflate/exhaustvalve 98, the ECU 96 may selectively provide air to the pneumatic supplyconduit 100, maintain air pressure within the pneumatic supply conduit100, or release air from the pneumatic supply conduit 100. In thisconfiguration, the ECU 96 may provide a desired pressure to the residuemanager cylinder 64 by adjusting the position of the inflate/exhaustvalve 98 via the actuators 108 and 110.

For example, to increase pressure to the cap end of the residue managercylinder 64, the ECU 96 will activate the solenoid 186, thereby drivingthe selection control valve 180 to the second position 184. The ECU 96will then activate the solenoid 110, thereby driving the inflate/exhaustvalve 98 to the second position 106. In the second position 106, airfrom the pneumatic source will flow into the pneumatic supply conduit100. With the selection control valve 180 in the second position 184,air from the pneumatic supply conduit 100 will flow through the valve180 and the pneumatic conduit 178 to the residue manager cylinder 64until a desired pressure within the cylinder 64 is achieved, as measuredby the pressure sensor 112. Next, the ECU 96 will instruct theelectronic actuator 186 to transition the valve 180 to the firstposition 182, thereby blocking air flow between the supply conduit 100and the cylinder 64. Consequently, pressure within the cap end of thecylinder 64 will be maintained at the desired pressure.

Conversely, to decrease pressure within the cap end of the residuemanager cylinder 64, the ECU 96 will transition the selection controlvalve 180 to the second position 184, which establishes fluidcommunication between the conduits 178 and 100. The ECU 96 will thentransition the inflate/exhaust valve 98 to the second position 104,which facilitates air flow out of the pneumatic supply conduit 100.Consequently, pressure within the cap end of the residue managercylinder 64 will decrease as air exhausts from the cylinder 64. Once theECU 96 receives a signal from the pressure sensor 112 that the pressurewithin the cap end of the residue manager cylinder 64 has reached adesired level, the ECU 96 will transition the selection control valve180 to the first position 182 which blocks flow to the pneumatic supplyconduit 178. Consequently, pressure within the residue manager cylinder64 will be maintained. In this manner, the ECU 96 may automaticallyregulate the contact force applied by the residue manager cylinder 64 inresponse to either operator input or detected residue cover. It shouldbe appreciated that transitioning the selection control valve 180 to thesecond position 184 and transitioning the inflate/exhaust valve 98 tothe first position 102 enables the pressure sensor 112 to measure thepressure within the cap end of the residue manager cylinder 64.

In the illustrated embodiment, the implement 10 includes a manual backupsystem 188 configured to facilitate manual control of the pneumaticcylinders 20, 44, 50, 56, 64 and 68 in the event of an electricalfailure. While the backup system 188 is described as “manual,” it shouldbe appreciated that pressure regulation within the down force cylinder20 and the depth control cylinders 44 and 68 will remain automatic, asdescribed above. In the present embodiment, the manual backup system 188enables an operator to adjust the pressure to each cylinder via a seriesof pressure regulators. As illustrated, the manual backup system 188includes a mode select valve 190 configured to automatically activatethe backup system 188 during an electrical failure. In the presentembodiment, the mode select valve 190 is a two position/three waypneumatic valve. The first position 192 is configured to enable air toflow out of a pilot conduit 194, while the second position 196facilitates air flow into the pilot conduit 194 from the pneumaticsource. An electronic actuator 198 (e.g., solenoid) regulates theposition of the mode select valve 190. While electrical power issupplied to the actuator 198, the actuator 198 holds the valve 190 inthe second position 196 such that air is provided to the pilot conduit194. In the event of an electrical failure, the mode select valve 190will transition to the first position 192 such that the air exhaustsfrom the pilot conduit 194.

Also in the illustrated embodiment, the pilot conduit 194 is in fluidcommunication with a series of actuators configured to control operationof a corresponding series of selection control valves. If the pilotconduit 194 is pressurized with the air flow from the pneumatic source,the selection control valves will remain closed, thereby disabling themanual backup system 188. However, in the event of an electricalfailure, the mode select valve 190 will facilitate air flow out of thepilot conduit 194, thereby inducing the selection control valves toactivate the manual backup system 188. Furthermore, an electricalfailure will induce the selection control valves 88, 136, 156, 168 and180 to transition to their respective first positions, thereby disablingautomatic control of the cylinders 20, 44, 50, 56, 64 and 68.

Each selection control valve 88, 136, 156, 168 and 180 configured tofacilitate automatic control of the cylinders 20, 44, 50, 56, 64 and 68has a corresponding selection control valve associated with the manualbackup system 188. For example, a first selection control valve 200 isin fluid communication with the pneumatic conduit 86 attached to theselection control valve 88 which regulates operation of the depthcontrol cylinders 44 and 68. The first selection control valve 200includes a first position 202 configured to facilitate air flow throughthe valve, and a second position 204 configured to block air flow. Apneumatic actuator 206 coupled to the valve 200 varies the position ofthe first selection control valve 200 based on air pressure within thepilot conduit 194. Specifically, the actuator 206 is configured totransition the first selection control valve 200 to the first position202 if air pressure is exhausted from the pilot conduit 194. In thisconfiguration, an electrical failure will induce the selection controlvalve 88 to transition to the first position 90 which blocks the flow ofair, and will induce the first selection control valve 200 to transitionto the first position 202 which facilitates air flow through the valve.Consequently, an electrical failure will disable automatic control ofthe depth control cylinders 44 and 68, while enabling manual control.

Similarly, a second selection control valve 208 is in fluidcommunication with the pneumatic conduit 134 attached to the selectioncontrol valve 136 which regulates operation of the down force cylinder20. The second selection control valve 208 includes a first position 210configured to facilitate air flow through the valve, and a secondposition 212 configured to block air flow. A pneumatic actuator 214coupled to the valve 208 varies the position of the second selectioncontrol valve 208 based on air pressure within the pilot conduit 194.Specifically, the actuator 214 is configured to transition the secondselection control valve 208 to the first position 210 if air pressure isexhausted from the pilot conduit 194. In this configuration, anelectrical failure will induce the selection control valve 136 totransition to the first position 138 which blocks the flow of air, andwill induce the second selection control valve 208 to transition to thefirst position 210 which facilitates air flow through the valve.Consequently, an electrical failure will disable automatic control ofthe down force cylinder 20, while enabling manual control.

In addition, a third selection control valve 216 is in fluidcommunication with the pneumatic conduit 154 attached to the selectioncontrol valve 156 which regulates operation of the closing disk cylinder50. The third selection control valve 216 includes a first position 218configured to facilitate air flow through the valve, and a secondposition 220 configured to block air flow. A pneumatic actuator 222coupled to the valve 216 varies the position of the third selectioncontrol valve 216 based on air pressure within the pilot conduit 194.Specifically, the actuator 222 is configured to transition the thirdselection control valve 216 to the first position 218 if air pressure isexhausted from the pilot conduit 194. In this configuration, anelectrical failure will induce the selection control valve 156 totransition to the first position 158 which blocks the flow of air, andwill induce the third selection control valve 216 to transition to thefirst position 218 which facilitates air flow through the valve.Consequently, an electrical failure will disable automatic control ofthe closing disk cylinder 50, while enabling manual control.

Furthermore, a fourth selection control valve 224 is in fluidcommunication with the pneumatic conduit 166 attached to the selectioncontrol valve 168 which regulates operation of the press wheel cylinder56. The fourth selection control valve 224 includes a first position 226configured to facilitate air flow through the valve, and a secondposition 228 configured to block air flow. A pneumatic actuator 230coupled to the valve 224 varies the position of the fourth selectioncontrol valve 224 based on air pressure within the pilot conduit 194.Specifically, the actuator 230 is configured to transition the fourthselection control valve 224 to the first position 226 if air pressure isexhausted from the pilot conduit 194. In this configuration, anelectrical failure will induce the selection control valve 168 totransition to the first position 170 which blocks the flow of air, andwill induce the fourth selection control valve 224 to transition to thefirst position 226 which facilitates air flow through the valve.Consequently, an electrical failure will disable automatic control ofthe press wheel cylinder 56, while enabling manual control.

In addition, a fifth selection control valve 232 is in fluidcommunication with the pneumatic conduit 178 attached to the selectioncontrol valve 180 which regulates operation of the residue managercylinder 64. The fifth selection control valve 232 includes a firstposition 234 configured to facilitate air flow through the valve, and asecond position 236 configured to block air flow. A pneumatic actuator238 coupled to the valve 232 varies the position of the fifth selectioncontrol valve 232 based on air pressure within the pilot conduit 194.Specifically, the actuator 238 is configured to transition the fifthselection control valve 232 to the first position 234 if air pressure isexhausted from the pilot conduit 194. In this configuration, anelectrical failure will induce the selection control valve 180 totransition to the first position 182 which blocks the flow of air, andwill induce the fifth selection control valve 232 to transition to thefirst position 234 which facilitates air flow through the valve.Consequently, an electrical failure will disable automatic control ofthe residue manager cylinder 64, while enabling manual control.

With each selection control valve 200, 208, 216, 224 and 232 in thefirst position, a flow path is established between the pneumaticconduits 86, 134, 154, 166 and 178 and respective pressure regulators.By adjusting air flow through each pressure regulator, pressure withinthe cylinders 50, 56, 64, 84 and 132 may be manually controlled. Asillustrated, a first pressure regulator 240 is fluidly coupled to thefirst selection control valve 200, and configured to receive an air flowfrom the pneumatic source. Consequently, when the first selectioncontrol valve 200 is in the first position 202, the first pressureregulator 240 may vary the flow of air from the pneumatic source to theconduit 86, thereby adjusting the pressure within the depth controlcylinders 44 and 68 via operation of the actuator 84. In the presentembodiment, a first pressure gauge 242 is coupled to the conduit 86downstream from the first selection control valve 200. In thisconfiguration, an operator may vary the pressure within the conduit 86by adjusting the first pressure regulator 240 until a desired pressureis shown on the first pressure gauge 242.

In addition, a second pressure regulator 244 is fluidly coupled to thesecond selection control valve 208, and configured to receive an airflow from the pneumatic source. Consequently, when the second selectioncontrol valve 208 is in the first position 210, the second pressureregulator 244 may vary the flow of air from the pneumatic source to theconduit 134, thereby adjusting the pressure within the down forcecylinder 20 via operation of the actuator 132. In the presentembodiment, a second pressure gauge 246 is coupled to the conduit 134downstream from the second selection control valve 208. In thisconfiguration, an operator may vary the pressure within the conduit 134by adjusting the second pressure regulator 244 until a desired pressureis shown on the second pressure gauge 246.

Furthermore, a third pressure regulator 248 is fluidly coupled to thethird selection control valve 216, and configured to receive an air flowfrom the pneumatic source. Consequently, when the third selectioncontrol valve 216 is in the first position 218, the third pressureregulator 248 may vary the flow of air from the pneumatic source to theconduit 154, thereby adjusting the pressure within the closing diskcylinder 50. In the present embodiment, a third pressure gauge 250 iscoupled to the conduit 154 downstream from the third selection controlvalve 216. In this configuration, an operator may vary the pressurewithin the conduit 154 by adjusting the third pressure regulator 248until a desired pressure is shown on the third pressure gauge 250.

The manual backup system 188 also includes a fourth pressure regulator252 fluidly coupled to the fourth selection control valve 224, andconfigured to receive an air flow from the pneumatic source.Consequently, when the fourth selection control valve 224 is in thefirst position 226, the fourth pressure regulator 252 may vary the flowof air from the pneumatic source to the conduit 166, thereby adjustingthe pressure within the press wheel cylinder 56. In the presentembodiment, a fourth pressure gauge 254 is coupled to the conduit 166downstream from the fourth selection control valve 224. In thisconfiguration, an operator may vary the pressure within the conduit 166by adjusting the fourth pressure regulator 252 until a desired pressureis shown on the fourth pressure gauge 254.

In addition, a fifth pressure regulator 256 is fluidly coupled to thefifth selection control valve 232, and configured to receive an air flowfrom the pneumatic source. Consequently, when the fifth selectioncontrol valve 232 is in the first position 234, the fifth pressureregulator 256 may vary the flow of air from the pneumatic source to theconduit 178, thereby adjusting the pressure within the residue managercylinder 64. In the present embodiment, a fifth pressure gauge 258 iscoupled to the conduit 178 downstream from the fifth selection controlvalve 232. In this configuration, an operator may vary the pressurewithin the conduit 178 by adjusting the fifth pressure regulator 256until a desired pressure is shown on the fifth pressure gauge 258.Because the pressure within each cylinder 20, 44, 50, 56, 64 and 68 maybe adjusted by the pressure regulators 240, 244, 248, 252 and 256, thebackup system 188 may facilitate manual control of the row unit 16 inthe event of an electrical failure.

FIG. 4 is a schematic diagram of an alternative pneumatic systemconfigured to automatically equalize a contact force of a press wheeland a gauge wheel. In the illustrated embodiment, a pneumatic conduit260 extends between the conduit 145 and a tandem press wheel valve 262.As illustrated, the tandem press wheel valve 262 is a two position/threeway pneumatic valve. The first position 264 is configured to facilitateair flow from the pneumatic conduit 166 to a conduit 266 in fluidcommunication with the cap end of the press wheel cylinder 56, whileblocking air flow from the conduit 260. The second position 268 blocksair flow from the conduit 166 to the conduit 266, while establishing afluid connection between the conduit 260 and the conduit 266. Anelectronic actuator 270 (e.g., solenoid) regulates the position of thetandem press wheel valve 262. The electronic actuator 270 iscommunicatively coupled to the ECU 96 which is configured to vary theposition of the tandem press wheel valve 262 in response to operatorinput (e.g., through the user interface 144).

While the tandem press wheel valve 262 is in the illustrated firstposition 264, air may flow from the selection control valve 168 to thepress wheel cylinder 56 via the conduits 166 and 266. In thisconfiguration, the ECU 96 may regulate the pressure within the cylinder56 via operation of the selection control valve 168 and theinflate/exhaust valve 98. However, to equalize a contact force of thepress wheel and the gauge wheels, the operator may input a command intothe user interface 144 instructing the ECU 96 to transition the tandempress wheel valve 262 to the second position 268. As previouslydiscussed, the second position 268 blocks air flow from the conduit 166,while facilitating air flow from the conduit 260. As a result, the ECU96 will not be able to regulate pressure within the press wheel cylinder56. Instead, pressure will be adjusted based on pressure within thedepth control cylinders 44 and 68.

With the tandem press wheel valve 262 in the second position 268, afluid connection is established between the depth control cylinders 44and 68 and the press wheel cylinder 56. Specifically, air may flow fromthe cylinders 44 and 68 through the conduits 80, 145, 260 and 266 to thepress wheel cylinder 56. In this manner, the contact force between thegauge wheels and the ground may be balanced with the contact forcebetween the press wheel and the ground. For example, certain variationsin the terrain may induce the gauge wheels to move upwardly relative tothe opener disks. In such a situation, pressure will increase within thecap end of the depth control cylinders 44 and 68. The increased pressurewill establish an air flow from the cylinders 44 and 68 to the presswheel cylinder 56, thereby driving the press wheel downwardly. Thedownward motion of the press wheel will drive the row unit 16 upwardly,thereby decreasing the contact force between the gauge wheels and thesoil. As a result, the pressure within the cap end of the depth controlcylinders 44 and 68 will decrease, thereby restoring the pressurebetween cylinders to equilibrium. Consequently, the contact force of thegauge wheels and the press wheel will be equalized, which maysubstantially reduce row unit vibration in response to contact withobstructions in the soil.

Conversely, certain variations in the terrain may induce the press wheelto move upwardly relative to the row unit chassis. In such a situation,pressure will increase within the cap end of the press wheel cylinder56. The increased pressure will establish an air flow from the cylinder56 to the depth control cylinders 44 and 68, thereby driving the gaugewheels downwardly. The downward motion of the gauge wheels will drivethe row unit 16 upwardly, thereby decreasing the contact force betweenthe press wheel and the soil. As a result, the pressure within the capend of the press wheel cylinder 56 will decrease, thereby restoring thepressure between cylinders to equilibrium. Consequently, the contactforce of the gauge wheels and the press wheel will be equalized, whichmay substantially reduce row unit vibration in response to contact withobstructions in the soil.

FIG. 5 is a schematic diagram of an alternative manual backup system 272configured to facilitate manual control of the pneumatic system.Specifically, the illustrated manual backup system 272 enables anoperator to control the pneumatic cylinders 20, 44, 50, 56, 64 and 68 inthe event of an electrical failure via a series of pressure regulators.As illustrated, the manual backup system 272 includes a series ofselection control valves having electronic actuators configured totransition the valves to an open position in the event of an electricalfailure. In this manner, the manual backup system 272 may be activatedwithout the use of the mode selection valve 190 and pilot systemdescribed above. Similar to the embodiment described with reference toFIG. 3, an electrical failure will also induce the selection controlvalves 88, 136, 156, 168 and 180 to transition to their respective firstpositions, thereby disabling automatic control of the cylinders 20, 44,50, 56, 64 and 68.

In the illustrated embodiment, each selection control valve 88, 136,156, 168 and 180 has a corresponding selection control valve associatedwith the manual backup system 272. For example, a first selectioncontrol valve 274 is in fluid communication with the pneumatic conduit86 attached to the selection control valve 88, which regulates operationof the depth control cylinders 44 and 68. The first selection controlvalve 274 includes a first position 276 configured to facilitate airflow through the valve, and a second position 278 configured to blockair flow. An electronic actuator (e.g., solenoid) 280 coupled to thevalve 274 varies the position of the first selection control valve 274based on application of electrical power. Specifically, while electricalpower is supplied to the actuator 280, the actuator 280 holds the valve274 in the second position 278 which blocks air flow through the valve274. In the event of an electrical failure, the selection control valve88 will transition to the first position 90 which blocks the flow ofair, and the first selection control valve 274 will transition to thefirst position 276, which facilitates air flow through the valve.Consequently, an electrical failure will disable automatic control ofthe depth control cylinders 44 and 68, while enabling manual control.

Similarly, a second selection control valve 282 is in fluidcommunication with the pneumatic conduit 134 attached to the selectioncontrol valve 136 which regulates operation of the down force cylinder20. The second selection control valve 282 includes a first position 284configured to facilitate air flow through the valve, and a secondposition 286 configured to block air flow. An electronic actuator (e.g.,solenoid) 288 coupled to the valve 282 varies the position of the secondselection control valve 282 based on application of electrical power.Specifically, while electrical power is supplied to the actuator 288,the actuator 288 holds the valve 282 in the second position 286 whichblocks air flow through the valve 282. In the event of an electricalfailure, the selection control valve 136 will transition to the firstposition 138 which blocks the flow of air, and the second selectioncontrol valve 282 will transition to the first position 284, whichfacilitates air flow through the valve. Consequently, an electricalfailure will disable automatic control of the down force cylinder 20,while enabling manual control.

In addition, a third selection control valve 290 is in fluidcommunication with the pneumatic conduit 154 attached to the selectioncontrol valve 156 which regulates operation of the closing disk cylinder50. The third selection control valve 290 includes a first position 292configured to facilitate air flow through the valve, and a secondposition 294 configured to block air flow. An electronic actuator (e.g.,solenoid) 296 coupled to the valve 290 varies the position of the thirdselection control valve 290 based on application of electrical power.Specifically, while electrical power is supplied to the actuator 296,the actuator 296 holds the valve 290 in the second position 294 whichblocks air flow through the valve 290. In the event of an electricalfailure, the selection control valve 156 will transition to the firstposition 158 which blocks the flow of air, and the third selectioncontrol valve 290 will transition to the first position 292, whichfacilitates air flow through the valve. Consequently, an electricalfailure will disable automatic control of the closing disk cylinder 50,while enabling manual control.

Furthermore, a fourth selection control valve 298 is in fluidcommunication with the pneumatic conduit 166 attached to the selectioncontrol valve 168 which regulates operation of the press wheel cylinder56. The fourth selection control valve 298 includes a first position 300configured to facilitate air flow through the valve, and a secondposition 302 configured to block air flow. An electronic actuator (e.g.,solenoid) 304 coupled to the valve 298 varies the position of the fourthselection control valve 298 based on application of electrical power.Specifically, while electrical power is supplied to the actuator 304,the actuator 304 holds the valve 298 in the second position 302 whichblocks air flow through the valve 298. In the event of an electricalfailure, the selection control valve 168 will transition to the firstposition 170 which blocks the flow of air, and the fourth selectioncontrol valve 298 will transition to the first position 300, whichfacilitates air flow through the valve. Consequently, an electricalfailure will disable automatic control of the press wheel cylinder 56,while enabling manual control.

In addition, a fifth selection control valve 306 is in fluidcommunication with the pneumatic conduit 178 attached to the selectioncontrol valve 180 which regulates operation of the residue managercylinder 64. The fifth selection control valve 306 includes a firstposition 308 configured to facilitate air flow through the valve, and asecond position 310 configured to block air flow. An electronic actuator(e.g., solenoid) 312 coupled to the valve 306 varies the position of thefifth selection control valve 306 based on application of electricalpower. Specifically, while electrical power is supplied to the actuator312, the actuator 312 holds the valve 306 in the second position 310which blocks air flow through the valve 306. In the event of anelectrical failure, the selection control valve 180 will transition tothe first position 182 which blocks the flow of air, and the fifthselection control valve 306 will transition to the first position 308,which facilitates air flow through the valve. Consequently, anelectrical failure will disable automatic control of the residue managercylinder 64, while enabling manual control.

Similar to the manual backup system 188 described above with referenceto FIG. 3, positioning each of the selection control valves 274, 282,290, 298 and 306 in their respective first position establishes a flowpath between the pneumatic conduits 86, 134, 154, 166 and 178 andrespective pressure regulators 240, 244, 248, 252 and 256. By adjustingair flow through each pressure regulator, pressure within the cylinders20, 44, 50, 56, 64 and 68 may be manually controlled. In the presentembodiment, a pressure gauge 242, 246, 250, 254 or 258 is coupled to arespective conduit 86, 134, 154, 166 or 178 downstream from theselection control valve. In this configuration, an operator may vary thepressure within the conduit by adjusting the pressure regulator until adesired pressure is shown on the pressure gauge. Because the pressurewithin each cylinder 20, 44, 50, 56, 64 and 68 may be adjusted by thepressure regulators 240, 244, 248, 252 and 256, the backup system 272may facilitate manual control of the row unit 16 in the event of anelectrical failure.

While the system described above employs pneumatic valves, cylinders andconduits, it should be appreciated that alternative embodiments mayoperate by transferring other working fluids throughout the system. Forexample, in certain embodiments, the implement 10 and row unit 16 mayemploy hydraulic valves, cylinders and conduits to establish a desiredforce and/or position of the ground engaging tools. In addition, whilethe system described above employs valves to control pressure within thecylinders, it should be appreciated that alternative embodiments mayutilize electrically controlled pressure regulators or other pressurecontrol devices. Furthermore, it should be appreciated that any suitableprotocol may be employed to convey signals between the electronicactuators and the ECU 96. For example, certain embodiments may employ aCAN bus to relay control signals between the tractor and the row unit 16or implement 10.

In addition, while the row unit 16 described above includes a down forcecylinder 20, depth control cylinders 44 and 68, a closing disk cylinder50, a press wheel cylinder 56, and a residue manager cylinder 64, itshould be appreciated that alternative embodiments may include fewercylinders for controlling the down force and/or position of the groundengaging tools. For example, in certain embodiments, the residue managerassembly 36, the soil closing assembly 32 and/or the press assembly 34may omit the actuating cylinders such that the assemblies are manuallyadjustable. Furthermore, while a single row unit 16 is shown coupled tothe pneumatic control system of the implement 10, it should beappreciated that the pneumatic control system may be employed toregulate pressure within cylinders of multiple row units 16. Forexample, in certain embodiments, a single pneumatic control system maycontrol each row unit 16 of the implement 10. Alternatively, multiplepneumatic control systems may be utilized to individually control arespective row unit 16 or a group of row units 16.

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

The invention claimed is:
 1. An agricultural implement system,comprising: a down force cylinder configured to apply a downward forceto a row unit; a depth control cylinder configured to vary a penetrationdepth of a ground engaging tool of the row unit; a down force controlvalve in fluid communication with the down force cylinder, wherein thedown force control valve is configured to regulate a flow of fluid tothe down force cylinder to adjust the downward force; and a down forcecontrol cylinder coupled to the down force control valve and in fluidcommunication with the depth control cylinder, wherein the down forcecontrol cylinder is configured to vary fluid pressure within the downforce cylinder by adjusting the flow of fluid through the down forcecontrol valve based on fluid pressure within the depth control cylinder.2. The agricultural implement system of claim 1, comprising a depthadjustment system configured to automatically maintain the penetrationdepth of the ground engaging tool by varying the fluid pressure withinthe depth control cylinder.
 3. The agricultural implement system ofclaim 1, wherein the ground engaging tool comprises an opener diskconfigured to be rotatably coupled to a chassis of the row unit.
 4. Theagricultural implement system of claim 3, comprising a gauge wheelassembly configured to be movably coupled to the chassis and comprisinga gauge wheel configured to rotate across a soil surface to limit thepenetration depth of the opener disk into the soil, wherein the depthcontrol cylinder is configured to extend between the chassis and thegauge wheel assembly, and the depth control cylinder is configured tovary the penetration depth of the opener disk by adjusting a position ofthe gauge wheel relative to the chassis.
 5. The agricultural implementsystem of claim 1, comprising: a press wheel assembly configured to bemovably coupled to a chassis of the row unit and comprising a presswheel configured to rotate across a soil surface to pack soil overdeposited seeds; and a press wheel cylinder configured to extend betweenthe chassis and the press wheel assembly, wherein the press wheelcylinder is configured to vary a contact force between the press wheeland the soil surface.
 6. The agricultural implement system of claim 5,wherein the press wheel cylinder is fluidly coupled to the depth controlcylinder to facilitate fluid flow between the press wheel cylinder andthe depth control cylinder.
 7. The agricultural implement system ofclaim 6, comprising a tandem press wheel valve configured to selectivelyblock fluid flow between the press wheel cylinder and the depth controlcylinder.
 8. The agricultural implement system of claim 1, comprising: aclosing disk assembly configured to be movably coupled to a chassis ofthe row unit and comprising a closing disk configured to rotate acrossthe soil surface to close a trench formed by the ground engaging tool;and a closing disk cylinder configured to extend between the chassis andthe closing disk assembly, wherein the closing disk cylinder isconfigured to vary a contact force between the closing disk and the soilsurface.